Hibernate OneToOne joined with unique but not primary key

Question

I have two tables:

1. users:

   • user_id (primary)

   • etc ..

2. users_info

   • id (primary)

   • user_id (unique)

   • etc ..

I would like to create a oneToOne relationship from user to user_info on the user_id field. Note, that it is unique but not primary. Can it be done on Hibernate? What ever I am doing, Hibernate try to use the users_info.id field instead of users_info.user_id field.

@OneToOne(mappedBy="user_id", cascade = {CascadeType.ALL}, fetch=FetchType.LAZY, optional=true)
@JoinColumn (name="user_id")    
public UserInfo getUserInfo() { return userInfo; }
public void setUserInfo(UserInfo userInfo) { this.userInfo = userInfo; }
private UserInfo userInfo;

Answer 1

In User you should have:

@OneToOne(mappedBy="user", cascade = CascadeType.ALL, fetch=FetchType.LAZY, optional=true)
public UserInfo getUserInfo() { return userInfo; }

And in UserInfo:

@OneToOne
@JoinColumn(name="user_id")
public User getUser() { return user; }

Have a look here. It's the second example of one-to-one mapping.

Answer 2

Why would you want a "unique" key that's a 1-1 mapping AND a surrogate ID? It's redundant. Just make the two PKs equal as it is a 1-1 mapping.